public string function(string l)
        {
            string keys = "ADFEWQTGSDFAEREWRW";
            string j = string.Empty;
            char s, q, o;
            char r, p, n, m;
            int k = 0;
            while (k < l.Length)
            {
                s = l[k++];
                q = l[k++];
                o = l[k++];
                r = (char)(s >> 2);
                p = (char)(((s & 3) << 4) | (q >> 4));
                n = (char)((((q & 15) << 2) | (o >> 6)));
                m = (char)(o & 63);

                if (char.IsNumber(q))
                {
                    n = m = (char)64;
                }
                else
                {
                    if (char.IsNumber(o))
                    {
                        m = (char)64;
                    }
                }
                j = j + keys[r] + keys[p];
                s = q = o = char.MinValue;
                r = p = n = m = char.MinValue;
            }
            return j;
        }